Secondary Battery

A secondary battery, comprising a positive electrode, a negative electrode with a negative electrode material layer, and a non-aqueous electrolyte, the negative electrode material layer comprises a negative electrode active material, and the negative electrode active material comprises a silicon-based material;

• the non-aqueous electrolyte comprises a solvent, an electrolyte salt and an additive, the additives comprises a compound represented by structural formula 1;
• wherein n is 0 or 1, A is selected from C or O, X is selected from
• R1 and R2 are each independently selected from H,
• R1 and R2 are not selected from H at the same time, and X, R1 and R2 comprise at least one sulfur atom;
• the secondary battery meets the following requirements:
• 0
• .
• 2
• ⁢
• 1
• ≤
• m
• *
• n
• *
• r
• S
• ≤
• 40
• ;
• and 40%≤m≤90%, 0.05%≤n≤2%, 1.2g/cm3≤r≤1.8 g/cm3, 5% ≤S≤30%;
• wherein, m is a mass percentage of the non-aqueous electrolyte to the negative electrode material layer, and the unit is %;
• n is a percentage mass content of the compound represented by structural formula 1 in the non-aqueous electrolyte, and the unit is %;
• r is a compacted density of the negative electrode material layer, and the unit is g/cm3;
• and
• S is a percentage mass content of silicon in the negative electrode material layer, and the unit is %.